Indicating or striker pin for electric fuses

Abstract

The current path of an electric indicating or striker pin fuse, and more particularly its fusible element, includes a point of maximum resistance where fusion of the latter must take place. That predetermined point is arranged in such a way that the pulverulent arc-quenching filler does not impair the proper operation of the indicating or striker pin device.

I claim as my invention: 
     
       1. A solderless indicating and striker pin device to be shunted across electric fuses comprising (a) a first fuse terminal (1);   (b) electroconductive pin means (5) conductively connected to said first fuse terminal (1) and spring (6) biased in a direction longitudinally thereof;   (c) a partition (9) of electric insulating material extending transversely to said pin means (5) and defining a passageway for the passage of said pin means (5) from a first space to one side to a second space to the other side of said partition (9);   (d) a second fuse terminal (2) arranged in spaced relation from said first fuse terminal (1);   (e) a fusible element (10) conductively connected with one end thereof to said second terminal (2) and engaging with the other and thereof said pin means (5) on said other side of said partition (9); and   (f) the point of engagement of said fusible element (10) and said pin means (5) being the point of highest resistance of the current path extending between said first terminal (1) and said second terminal (2) so that a break of said fusible element (10) will be initiated at said point by the highest generation of heat at said point.   
     
     
       2. A solderless indicating and striker pin device as specified in claim 1 wherein said fusible element is wound helically and embedded in a mass of arc-quenching filler (13) obstructing by friction operation of said device if the point of fusion is situated anywhere in said arc-quenching filler (13), and wherein proper operation of said indicating and striker pin device is assured by the fact that the point of engagement of said fusible element (10) and said pin means (5) is the point of highest resistance in the current-path extending between said first terminal (1) and said second terminal (2). 
     
     
       3. A solderless indicating and striker pin device as specified in claim 1 wherein the end of said pin means (5) in said second space is flattened and provided with a hole (5b) through which said fusible element (10) is threaded and wherein the point of highest resistance of the current path extending between said first terminal (1) and said second terminal (2) is the interface between said hole (5a) and said fusible element (10). 
     
     
       4. A solderless indicating and striker pin device as claimed in claim 1 wherein said first terminal (1) is provided with a bore (1b), a first tubular member (4) of metal being inserted into said bore (1b), said pin means (5) and said spring (6) being inserted into said tubular member and closed on one end thereof by said partition (9), wherein a second tubular member (14) of electric insulating material is arranged in coaxial relation to said first mentioned tubular member (4) and in abutting relation to said partition (9), said second tubular member (14) housing the point of engagement of said fusible element (10) and said pin means (5), and wherein said first mentioned tubular member (4) is filled with a pasty substance (8) at the end thereof adjacent said partition. 
     
     
       5. A solderless indicating and striker pin device as specified in claim 3 wherein said pasty substance is silicone grease (8).